Mercury MerCruiser Service Manual page 479

Ref. No. Qty.
1 1 Exhaust manifold assembly
2 10 Expansion plug
3 1 Gasket
Screw (0.375‑16 x 4.75)
4 6
5 1 Catalyst (ECT only)
6 1 Oxygen sensor—narrowband (ECT only)
7 1 Elbow assembly
2 Screw (0.250‑20 x 0.380 hex flange head) (ECT)
8
1 Screw (0.250‑20 x 0.380 hex flange head) (non‑ECT)
2 Cover bracket (ECT)
9
1 Cover bracket (non‑ECT)
10 1 Post O2 sensor plug (non‑ECT)
11 1 Copper washer (non‑ECT)
Screw (0.375‑16 x 2.5 hex flange head)
12 4
Gasket, elbow to manifold with open water ports (seawater
13 1
cooling)
Gasket, elbow to manifold with blocked water ports (closed
13 1
cooling)
14 2 Brass pipe plug (0.25‑8)
15 1 Brass pipe fitting (seawater cooling) (0.750‑4)
16 1 Expansion plug
17 1 Exhaust manifold temperature sensor assembly
1 Seawater cooling uses #28
18
2 Straight fitting (0.750‑14) (closed cooling)
19 1 Fitting assembly—seawater cooling
20 1 O‑ring
21 1 Ball
22 1 Fitting
23 1 Rubber ball seat
24 1 Straight fitting (0.750‑14) (closed cooling)
25 1 Brass plug
26 1 Straight fitting (0.750‑14) (closed cooling)
27 2 Wideband oxygen sensor
28 1 Straight fitting with threaded hole (0.750‑14 with 0.25‑18 hole)
29 1 Check valve
90-8M0099748 eng DECEMBER 2015
Description
4
1
6
3
2
Exhaust Manifold and Elbow Exploded View
First
Second
2
5
3
Final
59457
First
1
Final
4
57899
© 2016 Mercury Marine
Manifolds and Elbows
Torque
Nm lb‑in.
27 –
54 –
54 –
50 –
11.6 102.6
50 –
46 –
46 –
50 –
16 142
50 –
50 –
50 –
50 –
50 –
50 –
Hand‑tight—plus two turns
16 142
Page 7B-5
lb‑ft
20
39.8
39.8
36.8
–
36.8
34
34
36.8
–
36.8
36.8
36.8
36.8
36.8
36.8
–